Since the invention of communication systems in the 19th century, the use of communication equipment has expanded to touch nearly all aspects of modern day life. Most industrialized countries enjoy a wide variety of transmitted communications, including, for example, telephones, television, radio, etc. While some such systems are simply passive receivers, many communication devices are interactive, that is, they permit both the receipt and transmission of signals that are converted from a carrier signal to a receivable output. In all such systems, it is necessary to have one type of transducers that will convert perceivable data, such as visual images and audible sounds, into the carrier format, and a second type of transducers that will reconvert the carrier format into the perceivable visual or audio information.
In most two-way communication systems, a user is provided with a microphone which converts audible sounds into the carrier format and a speaker which converts the carrier format to reproduce the audible sound. In early communication systems, the microphone and speaker(s) were structured as separately housed components so that the microphone could be positioned immediately forward of the mouth while the speaker(s) were positioned proximate to the ears. For example, early telephones had a speaker connected to a cord so that the user could hold the speaker proximate to his/her ear while speaking directly into the microphone portion of the telephone. Radios commonly used earphones for speakers which were clamped over the head and ears while the user spoke into a separate microphone.
The physical structure of telephones, of course, developed further into the well-known hand-held receivers that are "dumb-bell" in shape and, of course, their more modern progeny. In these receivers, the speaker and microphone are housed in a common shell but are physically separated from each other a distance approximating the distance between the mouth and ear of an adult user. This physical spacing allowed the microphone to be placed forward of the mouth while the speaker, i.e., the earphone, was placed proximate to the ear. This physical separation reduced the likelihood of feedback wherein the audible signals produced by the speaker would be received by the microphone and retransmitted. Notwithstanding the improvements of such hand-held receivers, a problem still remained in that the user was required to hold the receiver in one hand against his/her head during use. Accordingly, the user only had one free hand which could be employed at other activities while utilizing the hand-held receiver. For this reason both "hands free" receivers and "speaker phones" were developed.
"Hands free" receivers have taken many forms. Prominent among these are those types of physical supports, such as brackets or cushions which were mounted to the receiver and which would allow the user to hold the receiver between his/her head and shoulder. A more recent "hands free" receiver employs a headset which positions a speaker earpiece in the ear and which includes a forward arcutately extending arm that supports a light-weight microphone forwardly of the mouth. The headset is held onto the head by means of a resilient bracket extending across the top of the head. While such headsets represent substantial improvement over prior receivers and are therefore quite popular, they nonetheless have the disadvantage of depending the microphone in front of the user's face which can be uncomfortable and distracting.
Speaker phones, of course, do not have the problem of speaker/microphone headsets. However, speaker phones suffer from transmitted sound quality due to the positioning of the microphone away from the user, usually by several feet. Furthermore, to prevent feedback, electronic cut-off circuitry may be employed so that activation of the microphone deactivates the speaker portion of the speaker phone. This naturally intrudes on the smoothness of any conversation and is an undesirable drawback of such systems.